| The first section of this thesis is concerned with the development and characterization of analytical sensors for the determination of biologically important species contained in liquid microenvironments. The goals are to address some potential problems that will arise when voltammetric sensors are used for in vivo voltammetry and to design, fabricate, and characterize new, structurally small voltammetric electrodes for analysis at the single cell level.;The voltammetry of ascorbic acid, 3,4-dihydroxy-phenylacetic acid, and dopamine is sufficiently different at polypyrrole-coated glassy carbon versus naked glassy carbon electrodes to allow the resolution of dopamine voltammetry from these two interfering species.;Ultrasmall ring-shaped carbon electrodes of micrometer dimension are characterized. These carbon ring electrodes exhibit charge-selective enhancement of oxidation rates for a series of catechols following anodic electrochemical treatment. This suggests that the carbon formed by the pyrolysis of methane contains charge-selective sites that affect the electron transfer process.;Data from carbon electrodes fabricated by low temperature, catalytic pyrolysis of ethylene on nickel is also presented. Fabrication of carbon microelectrodes by ethylene pyrolysis on nickel is accomplished and holds the promise to fabricate smaller carbon electrodes than previously possible.;The second section of this thesis discusses the electrochemical properties of ferrocene-substituted phosphazenes and polyphosphazenes. The first thermodynamic and kinetic data concerning ferrocene-linked phosphazene oxidations are presented including the largest reported positive shift in the oxidation peak potential for a substituted ferrocene. Thermodynamic and kinetic data for the oxidation and reduction of ferrocene-substituted polymers are presented. These include an unexpected enhanced rate of charge transport through bridged ferrocene-substituted polyphosphazenes relative to the pendent ferrocene-substituted polymer. |
